


Azure Awakening

by KannaRaimi



Category: Ao no Exorcist | Blue Exorcist
Genre: As nice as satan can get any way, Canon-Typical Violence, Demon Puberty, Demon Sex, F/F, F/M, Horny Demons, Horny Teenagers, Human Yukio, M/M, Multi, Nice Satan
Language: English
Status: In-Progress
Published: 2016-09-03
Updated: 2016-11-24
Packaged: 2018-08-12 18:08:05
Rating: Mature
Warnings: Graphic Depictions Of Violence, Underage
Chapters: 3
Words: 4,364
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7944196
Author URL: https://archiveofourown.org/users/KannaRaimi/pseuds/KannaRaimi
Summary: <blockquote class="userstuff">
              <p>Rin awakens his inner demon, and now must learn to control both aspects of himself. </p>
<p>With his scheming, Demon King, brothers teaching him about his demon body and his human friends teaching him about his human heart, Rin will grow into a proper demon prince. </p>
<p>Set B4 Yukio awakens. He won't in this AU. Yukio is 95% human and Rin is 5% human.</p>
            </blockquote>





	1. The Awakening

Rin and his friends had just finished celebrating Izumo's birthday. Being able to spend time with all his friends, and show off his cooking some more, had put Rin in an extremely good mood.

Going home content for once; Rin decided to try his meditation training, hoping this new mood would be the difference he needed to master his flames for good.

Settling into a comfortable position on the floor of his and Yukio's room, Rin relaxed and focused his senses within himself, not even a minute into the meditation Rin was confronted with a blue flame so bright it stung his eyes.

_‘It feels like strength, like home, like safety. This is my flame, this is me.’_

Sensing that he must keep moving forward, Rin dove headfirst into the flames and saw a cage made of blue fire, surrounded by a gray mist; inside he sees a baby cat demon, with horns made of blue flames, curled into a ball inside the tiny cage.

The size of the cage, he knows intuitively, is a result of the age in which his heart was sealed inside the Kurikara. Eyes full of curiosity, Rin approached the cage with haste.

Grabbing the fiery prison and peering through the bars, Rin sees that this demon has not aged past that of a newborn. Rage engulfs Rin, at seeing the tiny kitten, with navy fur, imprisoned. Without thinking, Rin rips the cage apart and cradles the newborn demon.

Said newborn looks in Rin's direction, with still closed eyes, and smiles. Holding the baby out at an arm's reach Rin gives a full faced smile back to the baby, and coos lightly. A blue flame erupts around the baby demon and extends to the still misty ground.

When the flames die down, Rin is shocked to see himself with cat-like features looking back at him. Pulling himself closer, Cat-Rin cradles his face in the crook of Rin's neck, and with a soft and melodic voice, very much like his own, Cat-Rin whispers into Rin’s next.

"Do you accept me?, do you finally accept me as a part of you?"

Knowing that this answer will cement his future, Rin felt this question resonate within him. Nodding his head in acceptance, Rin came to a quick, easy conclusion.

"You are me, and I am you. It's time I stop running from the me, I've avoided for so long."

Cat-Rin smiled pleasantly against Rin’s neck and whispered, "We have _15 long years_ of growth and development to catch up on. I'm sorry, we’re going to fuse and you'll no longer be able to _pretend you're human_."

And with that Cat-Rin transformed into a giant navy-coloured cat (almost twice the size of Kuro) still with flame covered horns, navy blue eyes and a lopsided grin.

Sliding his paw out of Rin's arms, the cat sat down in front of Rin and tapped said paw on his chest, where his heart should be. The bright blue flames took over Rin’s vision, and blind the melodic voice of Cat-Rin echoed softly in his head.

"It's time to wake up Rin, we are one."

Jolting awake at the blaring sound of his alarm clock, Rin instinctively knew that he had just met with his inner beast, his heart. Getting up from his seated position on the floor and stretching, Rin found himself surprised at the lack of stiffness in his body.

Bending his back past his normal thresholds, Rin accidentally released his claws and stabbed himself. Yelping, Rin leaps into the air. Hissing, he rubs his lower back as he walks down the hall to the stairs.

Upon reaching the stairway, Rin was engulfed in the smell of waffles and cinnamon oatmeal. Surprised, Rin took a bigger whiff to see what he could smell.

He located a sharp flamed metallic smell coming from his and Yukio's room, as well as a windy alcoholic breeze, and a fiery spice smell from the kitchen downstairs. Rin figured that that must be Yukio, Kuro, and Ukobach.

He jumped down the stairs, landing in a crouch, and playfully growled at Kuro. Kuro, having smelled the change in Rin overnight, was completely prepared for this reaction to his presence.

Running out the front door and enlarging himself, Kuro responded with a playful growl back and a snap of his jaw. Rin ran as fast as he could to catch the speeding Kuro, so fast that he caught up to the demon before Kuro could blink.

Running on pure instinct, Rin picked up Kuro by his giant neck and threw him about 200 ft into the air. Jumping into the air after him Rin begins tickling, nipping, and lightly scratching all over Kuro as the start their slow descent.

Rin had reduced Kuro into a mass of laughing and purring fur, all in the span of 2 mins. Grinning wildly, Rin dived head first towards the ground. Only turning to flip at the last second, just in time to land smoothly and catch the still overcome Kuro in one hand.

The cocking sound of two pistols being loaded sobered up Kuro's drunken smile, but only served to to enhance the blunettes. As azure eyes met teal, steely gazes clashed.

This heated staring contest was only interrupted by the poof of Kuro shrinking down to normal size and hiding behind Rin.

Yukio trained both muzzles on Rin's head, and grit his teeth.

“Who are you, and how have you invaded my brothers body?”

Causing Rin to laugh, an honest true laugh that shocked his younger brother into lowering his guard in confusion. Seizing the opportunity, Rin rushes to his brothers side before the teal-eyed twin could blink and pulls him into a bone-crushing hug.

"Yuki! I feel alive, truly alive today! My senses are so strong now, I can even smell the similarities in the blood we share."

Bearing with the pain, Yukio allowed his younger brother to man handle him.

"We have the same mother Nii-san."

Putting away his weapons, Yukio inspected Rin. Upon finding no drastic abnormalities; aside from the tail, razor-sharp teeth, pale skin, and pointed ears; he asked what had changed.

Rin told his brother all about the other him and what it had whispered. Yukio worried at the last warning; mentally recapping what the past 15 years would normally mean to a demon and paled.

While Rin scarfed down breakfast and chatted with Ukobach, Yukio called Mephisto's phone and explained what had happened.

Which immediately only proved his cause for concern, as Mephisto was already aware of the change and had already made some arrangements.

All Exwires would now stay in the dorm with the Okumura brothers with Shura as the female exwires guardian. They would all need to be told what to expect from Rin for the next few weeks, until he moved on to the next stage of his maturity.


	2. The Reintroduction

**Summary for the Chapter:**

> Rin's classmates get to imprint themselves into Rin's new demonic perception, but he also imprints himself into their human perception.
> 
> They don't get long to absorb each other tho, as Mephisto wants to start a new game. One the Vatican approved but doesn't trust.

Upon hearing that his friends were coming to live with him, Rin ecstatically grabbed Yukio's rough hands and pulled him into his strong embrace and through the fast-paced waltz.

Surprised, Yukio played the part of the girl as his brother elegantly danced them around with such speed and grace, it was a wonder if Rin didn't practice with a professional.

Being spun around in a difficult position was surprisingly calming for Yukio, as he stared at the manic grin on Rin's face. At least it was, until Rin's tail wrapped around his waist and he was being spun at break-neck speeds.

Rin caught him so smoothly and dipped him so low, Yukio could sense the ground beneath him. From his vantage point,  Yukio could truly see all the demonic features he and Rin had been ignoring for months. 

The strength barely contained by Rin's lithe form, the energy humming just beneath his pale skin, his blue hair framed his  _very_ pointed ears, and his youthful face that held razor-sharp teeth and his ridiculous eyes.

Yukio stared into Rin’s eyes in amazement. Rin's eyes were an unnatural blue, as deep as the ocean and yet as bright as the sky. Yukio had seen them wide and innocent, as well as narrow and angry. He had seen them sad and teary, as well as dull and vacant; and yet he had never known how beautiful and heartbreaking they were. 

Something nagged at him, from the back of his mind, while he lost himself in Rin's eyes.

_'How could Rin be so charming? How is my uselessly destructive Nii-san, this suave? The boy everyone was afraid of, the demon-child...'_

"Nii-san. I am human, please release me from your hypnosis completely. I have no defense against this, and cannot move."

Rin pouted but closed his eyes and set Yukio on his feet. The moment Rin let him go, Yukio could feel his mind ' _click_ ' back into focus. In that second Yukio shot Rin in the foot, or at least he would have had Rin not flipped out of the way. 

"Please entertain yourself until the other exwires arrive. "

* * *

 

Rin watched with due diligence as the Exwires bit by bit assembled, with their luggage, outside his dorm. Tail lashing out excitedly at the prospect of new playmates, Rin purred with excitement.

Mephisto had reissued rooms before they arrived, so that the girls each had their own room on the 3rd floor and the males each had their own room on the 2nd.

The roof had been transformed into a greenhouse, and the backyard into a sparring ring. Complete with a tally chart and huge chests of gear.

Rin pounced as the last Exwire, Shiemi, arrived. Only to be stopped by Mephisto snatching him back by his neck and slamming him into the ground.

"Allow them to settle and then we'll give you a chance to refamiliarize yourself with your friends."

Tossing an earthy green hamster at Rin, Mephisto watched from his floating chair as the Exwires set up their stuff in the old dorm and returned to the front courtyard.

Rin was very busy with examining and chasing the whining green hamster that smelt like family. Everytime he caught the hamster, it wiggled out of his grasp somehow. 

When the exwires had all returned, Mephisto ordered they line up a good five meters apart from each other and one by one greet Rin as honestly as they could.

When the Exwires were ready, and anxious to see their friend, Mephisto took back the now purring green hamster Rin was petting, and turned the whining half-demon back towards his friends.

Yukio, being first, called out a simple "Hello, Nii-san", and smiled an honest smile at the child-like wonder apparent on his twin's face.

Rin grabbed his face and peered deep into his brother's worried eyes, inhaling his flaming metallic scent, before hugging him tightly. Grinning, Rin nipped Yukio's ear and wrapped his tail around his wrist, while rubbing his face into Yukio's neck.

Izumo's giggle distracted Rin from teasing the mildly shocked Yukio. Moving onto her next, he crouched in front of her and waited to be addressed.

"Whatcha waiting for idiot?"

Called out a still grinning Izumo with her hands on her hips.

Rin grabbed her pale manicured hands and inspected them thoroughly, then moved onto her wind blown purple pigtails, stopping at her, slightly startled, but determined red eyes.

Izumo smelled like spring winds and sour plums, and a comforting Gehennian undertone that Rin enjoyed thoroughly.

Rin picked her up by her waist and spun, causing Izumo to freak out. She sighed and pet his head when he stopped and just hugged her.

Rin, smiling, whispered into her neck, "You smell like kin, eyebrows." Izumo punched Rin in the head, and grumbled as he gently put her down.

Stepping back, Rin moved on to crouch in front of Konekomaru. Rin tilted his head and waited for permission. A meek nod, and his inspection continued. Konekomaru was frail so Rin was extremely careful when he embraced the natural scholar.

Rin tentatively sniffed Konekomaru's head, and pulled back in surprise. Konekomaru, of course, smelt of ink and parchment, but underneath that, his natural scent, was of rain and the shockingly sweet smell of what Rin would later learn was a lotus flower.

Sniffing again to make sure he was correct; Rin all but shoutedin surprise.

"You smell like a girl! I can tell you're a boy somehow but the scent is very feminine.

Embarrassed, Konekomaru violently shooed him on towards the gasping Shima, who had been laughing so hard he'd choked on air.

Crouching down in front of Shima, Rin shot Konekomaru an apologetic look and waited for Shima to calm down and greet him. Konekomaru smiled weakly and shrugged his shoulders, just as Shima finally managed to quell his laughing fit.  
  
"Come here Okumura; although I'd rather a pretty girl."

Winking at Konekomaru, Shima opened his arms expecting a hug, but Rin sniffed around his wrists in confusion. Shaking his head in frustration, Rin finally gave in and hugged Shima.

Shima's scent was that of citrus, salt, and hair dye. but it seemed to be masking that of Gehena and one of his kin.  
  
"You smell of two orhers. You know one of my brothers; one I haven't met?", was all Rin whispered as he tightened his hold on Shima, who had stiffened and was trying to back away, before letting him go completely. Smiling at him, with sad eyes, Shima ruffled his blue hair and Rin nipped at his hand before moving on to Shiemi.  
  
Shiemi jumped up and hugged Rin first, Rin catching her easily. Twirling her around and setting her back down, Rin got a really good whiff of the green eyed girl.

Shiemi smelled of Earth and a mixture of different flowers, the strongest of which was lavender, and reminded him of the green hamsters scent but watered down and feminine. "You smell like a garden."  
  
"Really?!", giggled Shiemi as she jumped up and down, boobs bouncing in delight. Rin nodded and walked to Bon, with a red-tinted face.

Crouched in front of Bon, Rin's tail swayed back and forth as he visually inspected him. Bon's relaxed face twitched in anticipation. Crossing his strong arms across his built chest, Bon nervously waited out Rin's inspection.

Shura, noticing his nervousness, gave a little cough and nodded her head in Rin's direction. Remembering Mephisto’s instructions, Bon held out his hand and greeted Rin.

"Hi... Rin."

The smile Rin gave Bon momentarily blinded him, making him realize that Rin had been nervous too.

Leaping onto him, Rin held tight onto Bon's neck and wrapped his legs around Bon's waist. Rubbing his face into the bleached streak of Bon's head, Rin blushed hard at the scent wafting off Bon. Bon smelt strongly of spices and wood, but the lingering scent of himself on Bon is what had Rin drooling.

Rin could feel himself getting excited, so he snuck his tail around Bon’s leg and caressed his bulge through the pants. Bon, red faced and panting, tossed Rin off his person, and glared at him.

“What the fuck! You idiot!”

Rin, landing in a crouch, could make out the embarrassed arousal in the boys scent, so he took no offense to the rejection. Izumo called Bon over to explain about demon customs, and Mephisto waved at Rin to continue.

Laughing jovially, Rin walked over to Takara. Takara presented the puppet with a small frown. Rin sniffed around the puppet and leapt back in shock. There was so much aura in the puppet, almost enough to be a person.

Staring at Tanaka, Rin whined in confusion. Tanaka merely lifed the puppet, who scoffed at Rin.

"Dumbass! Whatcha gawking at? Get a move on, already!"

Shura grabs his head and immediately shoves him into her breasts, cooing at him.

"Aww! Look at ya’, growin’ up and gettin’ stwoooong!"

Swinging him back and forth in her bosom, to Shima's jealous whining, Shura smothered him in her scent, rubbing her face all over his head. Rin's tail sporadically swayed back and forth, from over stimulus.

Dropping him, Rin crawled away and pouted a few feet away from her. "Danger! You smell like booze and snake's venom! You scary devil-woman!", screamed a panicked Rin.

Shura snickered behind her hand and tossed an envelope in front of Rin. It smelt of holy water, so Rin jabbed his finger on it cautiously.

The burning sensation on his finger tip was all he needed to confirm his fears, and removed his finger at once. Staring at the now smoking appendage, Rin's face contorted with anger.

Hissing at the envelope, Rin's eyes dilated and he scrambled behind Mephisto and lit his he hand on fire to cancel out the holy water. Mephisto chuckled, handing the green hamster over to Rin and peered down at the now arguing exorcists.

"Why would you give him an envelope drenched in holy water, Shura?! Whose orders are you following?!"

Yukio accused, pistols already cocked and aimed at Shura's head.

"Calm down foureyes! It was either me or Angel. The Vatican has **demanded** we find his weaknesses while he is still growing into his powers. Angel is petitioning to just kill him, seeing as Kurikara is about to be useless; right Mephisto?"

Shura yelled in Mephisto's general direction, never taking her eyes of Yukio, sword already drawn and ready.

Bon jumped in the middle of their stand off at that.

"What do you mean by _Kurikara will be useless_?"

Yukio and Shura lowered their weapons and stared at Mephisto's lowering chair. As it touched the ground Mephisto smirked.

"Exactly what she said, dear boy. Once Rin masters his demon heart, Kurikara will be empty once more, and it will be entirely up to Rin when he unleashes his flames.

"The role the Koma sword was _chosen_ to play is almost at an end. Don't you want your family treasure back, Suguro-kun? The fire sword that contained even the flames of Satan’s spawn, the mighty Kurikara."

At Bon's startled face, Mephisto made eye contact with the green hamster, again being chased around playfully by Rin, and nodded.

The hamster squealed excitedly, just as Rin caught him. With a puff of smoke, Amaimon appeared and picked up the pouting Rin. Petting Rin's head, to Rin's immense happiness, Amaimon rolled his eyes at the startled bunch of exwires and their on-guard teachers.

"Until then it will be up to all us with demonic blood in our veins to teach Rin how to behave as a _proper gentleman_. As he is now, he is but a newborn with no allegiance to any side of the war," continued Mephisto, "Which is why _you all_ will now be living with him."

Pointing at Amaimon, who was currently playing a **very** rough version of tag with Rin, Mephisto smirked.

"At this current time, Rin can only see the destructive and volatile behavior of Amaimon, _both past and present_ , as an older brother wanting to play with him because **that,** ” pointing at Rin telephone punching Amaimon into the sky,“is how demons **play."**

"As his oldest brother, I am the one he finds the most comfort in. It's just how a newborn demon thinks; and because of this it is **your** job to make sure his human half does not **_"fall prey to my inhuman influence"._** So says the Vatican."

The grin of Mephisto's face grew as he looked towards Shura to add on. Shura grabbed her hip and grimaced.

"Che. Should y'all fail, I’ve been instructed to find as many a' Rin's weaknesses as possible, if I don't, they'll send **_baldy_ ** here to do it instead a' me."

Yukio hummed, thoughtfully, and pushed up his glasses.

"Please continue your work then, add holy water to your list."

Yukio stopped and asked thoughtfully, "Will either of _you_ be staying here with us?", glaring at Amaimon as he kicked Rin's head into the ground and then turned and ran.

Mephisto's smirk changed to a wide smile, as he spun in a circle. Bowing slightly, Mephisto slowly turned his head towards Rin and Amaimon.

"Oh no! I could never trust that idiot to restrain himself without my presence. However we _could_ stay for dinner on the weekends, as that is when I have decided we will come for Rin."

"As today is Friday, we will be here all day after cram school. I have excused you all from first and second period, but you should really try to get to there by lunch. Rin will stay with me the entire day, don't worry, he will be _very_ safe."

Mephisto grinned darkly and started twirling his umbrella, "You will only have four days to undo the more ... _demonic_ _and cruel_ parts of my teachings, and I'll have  three whole days to **eliminate** the more _humane and limiting_ parts of your teachings."

Konekomaru's hand snapped to his glasses as he cleared his throat to gain the groups attention.

“The way you worded that seems a bit strange. _We_ have the bigger portion of the week and yet you insinuated that _you_ had an advantage. Will you explain?”

Mephisto's face stretched into a menacing smile as he watched Rin and Amaimon wrestle violently in the yard, both grinning widely.

“Right now, **Rin is more demon than human.** "

"I'll make it simple, for you. Rin inherited most of Yukio's powers as well as his own. **Most.** The amount of demon blood left in Yukio, is the amount of human blood left in Rin right now."

"It would take Satan himself to activate Yukio's demon blood, so imagine what it's going to take to make Rin relatively human again. Especially when you consider how unfit for human society he was _before_ he awakened his flames. Just ask Okumura.”

A quick shake of his head and a frown was all the Exwires got as explanation from Yukio.

Snapping his fingers and grinning widely, Mephisto bowed to the humans as his chair appeared behind him. Sitting down and snapping again, Amaimon appeared next to the chair with Rin crouched on his shoulder.

Tossing Rin an ice pop, and Amaimon an enormous lollipop, Mephisto counted in German and disappeared.

Izumo grit her teeth and Shima sighed. Bon shook his head and looked off towards the school.

"Our classes with Rin start Monday."

Stated Yukio, pushing his glasses back up his nose, as he pulled out a notepad and a pen.

"Let's start planning before we have to get to school. I think, between Konekomaru and I, we can figure out a plan."


	3. The Plan

**Summary for the Chapter:**

> An outline for the next month or so. The training schedule for our lovely nekoRin. No he doesn't have cat ears in his humanoid form, and he won't get them at any point in this story.

**Notes for the Chapter:**

> I'm sorry this is short and drawn out, but I am in the US Army and I was just stationed in a new place. My schedule will be hectic and doesn't allow for much free time.

Konekomaru sat across from Yukio at the dining room table, tapping his pen thoughtfully. “Well, we only get four days to teach Rin each week. I propose we separate the lessons by days.” 

Yukio nods at him to continue as he writes the plan down. “On Mondays we can try to reintroduce human customs and behaviors; so that he doesn't try to bite us or steal babies from weak parents.” 

Shiemi gasped, jumping up out of her seat, “Rin wouldn't do that; he's too nice! He may be a lot stronger now, but he's not evil.”

“You idiot! No one's accusing Rin of being evil.”, Izumo scoffed disdainfully, “Nice demons often take children away from weak parents in an attempt to raise them properly, so that they don't become orphans later on.” 

Getting up in Shiemi's face, Izumo practically growled. “You should know some of these things by now, you're a tamer. You're familiar is a baby greenman. Haven't you ever wondered if he has parents, or how he ages, or even what he eats!?”

Shiemi crumpled in herself, blushing, “I-It… I nev-” Shiemi was saved by Shima sighing loudly and poking Izumo, hard, in the ribs. “Isn't it your job as a seasoned tamer to teach her what's expected of her.”

Izumo flushed, folded her arms across her chest, and glared at the floor. Konekomaru cleared his throat and tapped his glasses irritably.

“Right. To demons, bites are like familial kisses that signify love for a family member. Animals do this in the wild as well. So on Mondays we’ll be reintroducing Rin to the human equivalents to demon customs.”

Konekomaru shifted to face Yukio across the table, and nodded. Yukio, taking the cue, tapped the notepad he had been writing on. 

“You will only instruct him on the customs you are proficient at. Make no mistake; you could lose your life! Rin is a cat demon, and the son of Satan. He will be moody, playful, and dangerous. If you are shaky in your teachings, we can only assume that Mephisto will erase them. That would be both a waste of our time and effort.”

Yukio turns back to Konekomaru, who nods and moves on. “On Tuesdays the best case scenario is we take him out into a semi-public area, and later public areas and crowded areas, as immersion therapy, but a worse case scenario is just a repeat of Monday.”

“Wednesdays should focus on academics and everyday uses for academics. To provide him not just with the information, but also a reason to retain the information. And our last day, Thursday, should be an Exwire day. Where we explain what Exorcists do and why it's necessary he remain one.”

Shura dropped her head hard on the end of the table, completely giving in to the daunting weight of the new task set in front of her.

“So my sword lessons with Rin won't happen until after he's been fully immersed back into human society. Why do these goals just keep stacking up?”

Yukio grinned at her from the other end of the table, as he ripped out the page and slid it around for everyone to look at. Getting up from the table and grabbing his backpack, Yukio made his last announcement to the table.

“Welcome to everyday of my life. Don't forget to initial next to the days you think you'll be most helpful. You are all unofficial demon trainers now, if we succeed you might get that officially added to your title.”

With those parting words, Yukio used a key to get to school and left the gate open for whenever the Exwires finished with the sheet.


End file.
